Antonio Spanò

New bacilli from shallow hydrothermal vents of Panarea Island (Italy) and their biotechnological potential

Aims:  To characterize bacilli isolated from shallow hydrothermal vents of Panarea Island (Italy) and evaluate their biotechnological potential.

CONVENTIONAL AND MOLECULAR METHODS TO DETECT BACTERIAL PATHOGENS IN MUSSELS

Aim:  To detect Aeromonas spp., Salmonella spp., Vibrio cholerae, Vibrio parahaemolyticus and Vibrio vulnificus in mussels and water samples from a farming area, conventional and molecular methods were applied to enrichment cultures.

Antiviral and immunomodulatory effects of a novel bacterial exopolysaccharide of shallow marine vent origin

To evaluate a novel exopolysaccharide (EPS1) from the recently described haloalkaliphilic, thermophilic Bacillus licheniformis strain T14, isolated from a shallow hydrothermal vent of Panarea Island (Italy), for its antiviral and immunomodulatory effects against herpes simplex virus type 2 (HSV‐2).

Abundance and Diversity of Picocyanobacteria in Shallow Hydrothermal Vents of Panarea Island (Italy)

The abundance and diversity of cyanobacteria living in sediments collected from six vents (temperature range 37–130°C) close to the Panarea Island (Italy) were studied. The diversity of cyanobacteria was analyzed by using a PCR-DGGE approach with group-specific primers. The greatest number and diversity of cyanobacteria were registered at the coldest vent. Sequencing of DGGE fragments revealed that most sequences matched with uncultured cyanobacteria deposited in databases and some were distantly affiliated with different species of Synechococcus. New, genetically distant ribotypes of cyanobacteria are the dominant oxygenic phototrophs in shallow hydrothermal system of Panarea Island.

Role of Bacterial Exopolysaccharides as Agents in Counteracting Immune Disorders Induced by Herpes Virus

Extreme marine environments, such as the submarine shallow vents of the Eolian Islands (Italy), offer an almost unexplored source of microorganisms producing unexploited and promising biomolecules for pharmaceutical applications. Thermophilic and thermotolerant bacilli isolated from Eolian vents are able to produce exopolysaccharides (EPSs) with antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2). HSV-2 is responsible for the most common and continuously increasing viral infections in humans. Due to the appearance of resistance to the available treatments, new biomolecules exhibiting different mechanisms of action could provide novel agents for treating viral infections. The EPSs hinder the HSV-2 replication in human peripheral blood mononuclear cells (PBMC) but not in WISH (Wistar Institute Susan Hayflic) cells line, indicating that cell-mediated immunity was involved in the antiviral activity. High levels of Th1-type cytokines were detected in PBMC treated with all EPSs, while Th2-type cytokines were not induced. These EPSs are water soluble exopolymers able to stimulate the immune response and thus contribute to the antiviral immune defense, acting as immunomodulators. As stimulants of Th1 cell-mediated immunity, they could lead to the development of novel drugs as alternative in the treatment of herpes virus infections, as well as in immunocompromised host.

Preliminary Study on the In vitro and In vivo Effects of Asparagopsis taxiformis Bioactive Phycoderivates on Teleosts

Several compounds from marine organisms have been studied for their potential use in aquaculture. Among the red algae, Asparagopsis taxiformis is considered one of the most promising species for the production of bioactive metabolites with numerous proposed applications. Here, the in vitro antibacterial activity, the easy handling and the absence of adverse effects on marine fish species are reported. Depending on the seasonal period of sampling, ethanol extracts of A. taxiformis exhibited significantly different inhibitory activity against fish pathogenic bacteria. The extract obtained in late spring showed strong antibacterial activity against Aeromonas salmonicida subsp. salmonicida, Vibrio alginolyticus, and V. vulnificus, and moderate activity against Photobacterium damselae subsp. damselae, P. damselae subsp. piscicida, V. harveyi and V. parahaemolyticus. Sea bass and gilthead sea bream were fed with pellets supplied with the alga and algal extracts. The absence of undesired effects on fish was demonstrated. Hematological and biochemical investigations allowed to confirm that the whole alga and its extracts could be proposed for a future application in aquaculture.

Poly-ó-Glutamic Acid from Bacillus Horneckiae Strain APA of Shallow Marine Vent Origin with Antiviral and Immunomodulatory Effects against Herpes Simplex Virus Type-2

The shallow vents of the Eolian Islands (Italy) are sources of almost unexplored microorganisms able to produce biomolecules with promising pharmaceutical applications. This work describes the characterization of an extracellular poly-γ-glutamic acid (γ-PGA) from the new Bacillus horneckiae strain APA, and its antiviral and immunomodulatory effects against Herpes simplex virus type 2 (HSV-2). The γ-PGA-APA was able to hinder HSV-2 replication in human peripheral blood mononuclear cells (PBMC), involving the cell-mediated immunity. The exopolymer induced the expression of high levels of Th1–type cytokines in PBMC, while it had no effects on Th2-type cytokines production. This is the first report on a γ-PGA produced by a marine thermotolerant B. horneckiae strain with antiviral and immunomodulator activities. As stimulator of Th1 cell-mediated immunity, this biopolymer could be potentially used in the treatment of immunocompromised hosts as well as in patients affected by herpes virus infections.

Anti-herpes simplex virus 1 and immunomodulatory activities of a poly-γ- glutamic acid from Bacillus horneckiae strain APA of shallow vent origin

Herpes simplex virus type 1 (HSV-1) is responsible of common and widespread viral infections in humans through the world, and of rare, but extremely severe, clinical syndromes in the central nervous system. The emergence of resistant strains to drugs actually in use encourages the searching for novel antiviral compounds, including those of natural origin. In this study, the recently described poly-γ-glutamic acid (γ-PGA-APA), produced by the marine thermotolerant Bacillus horneckiae strain APA, and previously shown to possess biological and antiviral activity, was evaluated for its anti-HSV-1 and immunomodulatory properties. The biopolymer hindered the HSV-1 infection in the very early phase of virus replication. In addition, the γ-PGA-APA was shown to exert low cytotoxicity and noticeable immunomodulatory activities towards TNF-α and IL-1β gene expression. Moreover, the capacity to positively modulate the transcriptional activity of the cytokine genes was paired with increased level of activation of the transcription factor NF-kB by γ-PGA-APA. Overall, as non-cytotoxic biopolymer able to contribute in the antiviral defense against HSV-1, γ-PGA-APA could lead to the development of novel natural drugs for alternative therapies.

Thermal restraint of a bacterial exopolysaccharide of shallow vent origin

To dynamically characterize the thermal properties of the fructose-rich exopolysaccharide (EPS1-T14), produced by the marine thermophilic Bacillus licheniformis T14, the Attenuated Total Reflectance Fourier Transform Infra-Red spectroscopy was coupled to variable temperature ranging from ambient to 80°C. The spectra were analyzed by the following innovative mathematical tools: i) non-ideal spectral deviation, ii) OH-stretching band frequency center shift, iii) spectral distance, and iv) wavelet cross-correlation analysis. The thermal restraint analysis revealed that the whole EPS1-T14 system possessed high stability until 80°C, and suggested that fucose was mainly involved in the EPS1-T14 thermal stability, whereas glucose was responsible for its molecular flexibility. Our results provide novel insights into the thermal stability properties of the whole EPS1-T14 and into the role of its main monosaccharidic units. As a new biopolymer, the thermostable EPS1-T14 could be used in traditional biotechnology fields and in new biomedical areas, as nanocarriers, requiring high temperature processes.

Bacterial Exopolysaccharide of Shallow Marine Vent Origin as Agent in Counteracting Immune Disorders Induced by Herpes Virus.

Herpes simplex virus type 2 (HSV-2) is responsible of the continuously increasing viral infections in humans. In a previous study we demonstrated that the exopolysaccharide produced by Bacillus licheniformis strain B3-15 (EPS-B3-15), was able to hinder the HSV-2 replication in peripheral blood mononuclear cells (PBMC) and this antiviral activity appear to be related to a significant stimulation of the Th1-cytokines. In this study we analyse the role of EPS-B3-15 on Th2 cytokine production by PBMC infected or not with HSV-2. EPS-B3-15 demonstrate the ability to induce a particular cytokine network with consequent effects on the immune cells during HSV-2 infection.